1. Global Distribution of the Solar Wind Flux and Velocity From SOHO/SWAN During SC‐23 and SC‐24
- Author
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Dimitra Koutroumpa, Eric Quémerais, Walter Schmidt, Stéphane Ferron, HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Analytic and Computational Research, Inc. - Earth Sciences (ACRI-ST), and Finnish Meteorological Institute (FMI)
- Subjects
Solar minimum ,Physics ,010504 meteorology & atmospheric sciences ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,Flux ,Energy flux ,010502 geochemistry & geophysics ,Atmospheric sciences ,Solar maximum ,7. Clean energy ,01 natural sciences ,Solar wind ,Geophysics ,Interplanetary scintillation ,13. Climate action ,Physics::Space Physics ,Astrophysics::Solar and Stellar Astrophysics ,General Earth and Planetary Sciences ,Astrophysics::Earth and Planetary Astrophysics ,Interplanetary spaceflight ,Heliosphere ,0105 earth and related environmental sciences - Abstract
International audience; We analyze SOHO/SWAN hydrogen Lyman‐α data collected between 1996 and 2018 to derive the solar wind latitudinal distribution over time. Full‐sky interplanetary Lyman‐α maps are inverted to derive the total hydrogen ionization rate latitude profiles, normalized to proton charge‐exchange and photoionization. Using Interplanetary Scintillation (IPS) velocities to calculate the velocity‐dependent charge‐exchange cross‐sections, we produce the solar wind flux latitudinal profiles. Finally, we compute solar wind velocity latitude profiles, based on the dynamic pressure and energy flux conservation (calculated from OMNI data) over latitude. SWAN reproduces the IPS velocity profiles up to at least ±60°, and also agrees with Ulysses in‐situ measurements for solar minimum periods in 1996‐1997 and 2007. During solar maximum, discrepancies are more frequent because in‐situ data reflect local solar wind conditions, while SWAN data reflect global conditions in the heliosphere.
- Published
- 2019
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